A 13-year-old boy has been detained in Louisiana for killing his 5-year-old sister after telling police he was trying to practice wrestling moves he saw on television.

(PHOTO:YouTube Clip/CNN)

Girl, 5, killed by 13-year-old brother practicing "WWE" moves.

The 13-year-old boy was home alone with his 5-year-old half sister, Viloude Louis, when he decided to practice some "WWE" wrestling moves that he had learned on television. Jumping on his sister, he threw a "slam punch and elbow" at her multiple times. Even after the girl cried out in pain, the boy told police that he continued to hit his sister for another three minutes until he was distracted by a call from his mother, ABC news reported.

After hanging up with his mother, the boy, whose name police would not release, said his sister complained of stomach pains and decided to go upstairs. He found her about half an hour later unconscious. He immediately called 911. At the hospital, it was discovered that Viloude was suffering from multiple injuries, including internal bleeding, broken ribs and liver lacerations. She was pronounced dead.

Police have now charged the 13-year-old with second-degree murder. He was held at Rivarde Juvenile Detention Center on Wednesday, where police say he failed to show any remorse.

Should the boy, 13, be charged with murder?

He "was smiling and appeared as though he took great pride in what he was doing," Col. John Fortunato told CNN on Wednesday. "He showed no remorse while he was being interviewed in the presence of his mother."

A statement the WWE, while referring to the situation as a tragedy, blamed the girl's death on a lack of parental supervision.

"The facts of this case clearly point to a lack of parental supervision. ... It is illogical to conclude that the repeated, brutal and ultimately fatal beating of a 5-year-old little girl by a teenager could be confused with imitation of WWE action seen on TV," the organization told CNN.